Endless helical conveyer and belt

ABSTRACT

An endless conveyor having an endless flat link belt driven in two concentric helical paths by concentric rotary drums which engage the inner edges of the belt inwardly of the two helical paths to push the belt upwardly along one path crossing over at the top and downwardly along the other path. The belt links along the inner edge of the belt are collapsible to enable the belt to assume different curvatures while the links along the outer edge of the belt have a greater longitudinal dimension to accommodate the greater radius of curvature along the outer edge of the belt. Because the belt is driven along its inner edge and moves in a helical path, each link is pivoted about the inner edge in the forward direction of conveyance thus placing the outer edge of the belt under tension at all times during operation.

0 United States Patent n51 3,664,487 Ballenger 1 May 23, 1972 [54]ENDLESS HELICAL CONVEYER AND BELT Primary Examiner-Edward A. SrokaAnorneyBeveridge and DeGrandi [72] Inventor: Carl H. Ballenger, 1751Circle Road, Ruxton, Md. 21204 57 ST Filed; y 1969 An endless conveyorhaving an endless flat link belt driven in two concentric helical pathsby concentric rotary drums which [2]] Appl' 827381 engage the inneredges of the belt inwardly of the two helical paths to push the beltupwardly along one path crossing over [52] U.S. Cl. ..l98/136 at the p nn r ly a ng h o r p h- Th elt nk [5]] 1m, (1| B65 17/06 along the inneredge of the belt are collapsible to enable the 58 Field of Search..l98/136, 181-182; belt to assume different curvatures While the linksalong the 3 147 outer edge of the belt have a greater longitudinaldimension to accommodate the greater radius of curvature along the outer56] Reerences Cited edge of the belt. Because the belt is driven alongits inner edge and moves in a helical path, each link is pivoted aboutthe UNITED STATES PATENTS inner edge in the forward direction ofconveyance thus placing the outer edge of the belt under tension at alltimes during 701,459 6/1902 Aston ..198/136 X operation 2,788,140 4/1957Becker 198/1 36 X 3,348,659 10/ 1 967 Roinestad ,.198/136 18 Claims, 12Drawing Figures PATENTEDHAY 23 1912 3, 664.48 7

SHEET 1 BF 4 INVENTOR CARL H. BALLENGER fj ig f MMZZ M ATTORNEYSPATENTl-inmwm 3,664,487

SHEET 3 OF 4 H0 4 INVENTOR CARL H. BALLENGER ATTORNEYS ENDLESS HELICALCONVEYER AND BELT SUMMARY OF OBJECTS AND INVENTION The present inventionrelates to an endless helical conveyer and to a belt incorporatedtherein. Although one application of the conveyer is for moving bakeryproducts such as bread loaves which have just been-baked, through acooling zone, it will be readily understood that the conveyer may beequally applied to advantage in other environments and that theinvention is not restricted to the baking industry.

One of the objects of the present invention is to provide a new helicalconveyer capable of conveying articles in ascending and descendinghelical paths.

A further object of the present invention is to provide such a helicalconveyer which occupies relatively minimum space considering the lengthof the path of conveyance. Included herein is the provision of such ahelical conveyer capable of conveying products upwardly and thendownwardly or vice versa through two concentric helical paths.

A further object of the present invention is to provide such a helicalconveyer which incorporates an endless link belt which helically ascendsand descends substantially in horizontal planes. Included herein is theprovision of a novel drive mechanism for driving the belt and whichinsures that the belt remains substantially flat during operation andwith the links in its outer edge under tension at all times.

Yet another object of the present invention is to provide an improvedlink belt particularly suitable for use in such a helical conveyer.

The above objects are achieved in a conveyer including a verticalsupport structure including a first set of horizontally projectingsupports arms spaced along a first helical path about a vertical axis; asecond set of horizontally projecting support arms spaced along a secondhelical path surrounding the first path; and an endless flat link beltsupported on the arms so that the belt extends helically along the firstand second paths with cross over or transition sections of the beltextending between the helical paths at the top and bottom of theconveyer. The belt is driven helically up one path and down the otherpath by means of two concentric rotary drums, one drum being mountedwithin the first helical path for rotation about a vertical axis, andthe other drum being mounted between the first and second helical pathsfor rotation about the same vertical axis. Extending vertically alongthe drums at circumferentially spaced locations thereon are a pluralityof elongated angle members with their corners projecting outwardly fromthe drums to engage in recesses formed along the inner edge of the beltto drive the belt in a pushing manner upon rotation of the drums.

Rotation of the drums is achieved by sprocket chains secured to thedrums respectively to extend in a horizontal plane circumferentiallyaround the drums. Drive sprockets are engaged in the chains so that uponrotation of the drive sprockets, the motion will be transmitted to thedrums to rotate the same for moving the belt along the helical paths.

The conveyer belt has a metallic link construction which in oneembodiment includes a plurality of rods extending transversely of thebelt and being linked together at their opposite ends to form the innerand outer edges of the belt. The links at one of the edges of the beltare larger than those at the opposite edge and thus constitute the outeredge of the belt when in use on the conveyer during which the outer edgeof the belt assumes a greater radius of curvature than the inner edge.In addition, the links along the inner edge of the belt are extendibleand collapsible towards or away from each other to permit the inner edgeto conform to the different curvatures existing along the inner edges ofthe two helical paths. Moreover the links along the inner edge of thebelt are formed with recesses for receiving the corners of the anglemembers on the drive drums thus enabling the belt to be positivelydriven by the drums without slippage. During operation, the belt rodsare pivoted forwardly (in the direction of conveyance) about the inneredge of the belt by the drive angles on the drums whereby the outer edgeof the belt is desirably maintained under tension throughout operation.

In use the conveyer may be continuously loaded with products on thelower run of one of the helical paths whereupon the loaded products willproceed upwardly along one helical path crossing over at the top of theconveyer and then descending along the other helical path to be removedat the bottom of the conveyer in any suitable manner.

Other objects and advantages of the present invention will becomeapparent from the following more detailed description taken inconjunction with the attached drawings in which:

FIG. 1 is a diagrammatic perspective view of a helical coneyer embodyingthe present invention;

FIG. 2 is a fragmental, plan view taken generally along lines 2 2 ofFIG. 1 illustrating a bottom section of the conveyer and associatedfeeding and unloading conveyers for supplying and removing products fromthe helical conveyer;

FIG. 3 is a plan view of the conveyer;

FIG. 4 is a vertical cross sectional view of the conveyer;

FIG. 5 is a transverse cross sectional view taken across bottom portionsof the conveyer illustrating the drive mechanism for the conveyer;

FIG. 6 is a fragmental, cross sectional view taken generally along lines6 6 of FIG. 4 illustrating a section of the conveyer belt and itsunderlying support;

FIG. 7 is an enlarged, fragmental plan view of a section of the beltshowing the inner edge thereof in extended or uncollapsed condition;

FIG. 8 is a view similar to FIG. 7 but with the inner edge of the beltin a collapsed condition;

FIG. 9 is an enlarged end view of another belt section taken along lines9 9 of FIG. 7;

FIG. 10 is an enlarged end view of the inner edge of the belt as shownin FIG. 7;

FIG. 11 is an enlarged end view of the inner edge of the belt as shownin FIG. 8; and

FIG. 12 is a fragmental perspective view of a top portion of a drivecylinder which drives the belt during transition between two helicalpaths in the conveyer.

DETAILED DESCRIPTION Referring to the drawings in detail, FIG. Idiagrammatically shows a helical conveyer l0 embodying the presentinvention and including an outer helical path designated 12 and an innerhelical path designated 14 concentric to the outer path 12. The innerand outer helical paths I2 and 14 are defined by an endless movable beltwhich will be described subsequently in more detail. At the top andbottom ends of the conveyer, helical paths l2 and 14 are interconnectedby transitional sections 16 and 18 of the belt respectively. Thus at thetop end of the belt or path, the transitional section 16 lessens indiameter while curving inwardly and downwardly in a helical manner tomerge into the inner helical path 14. At the bottom of the conveyer,transitional section 18 gradually increases in its diameter whilecurving outwardly to merge into the outer helical path as shown in FIG.2.

The lower run or loop of the outer helical path 12 is formed in twosections 20 and 22 lying at different elevations and interconnected by avertical section 23 as shown in FIG. 1. Movement of the belt throughsections 20, 23 and 22 is guided by vertically spaced rollers 25 overand under which the belt travels. Moving clockwise in the direction oftravel as indicated in FIG. 2, after leaving section 22,the belt risesthrough a vertical section 26 diagrammatically opposite vertical section23 after which the belt continues along a helical path upwardly throughthe successive loops or convolutions which form the outer helical path12.

In the shown embodiment, the products or articles (not shown) to beconveyed are loaded in any suitable manner such as by a conveyer 27 onthe lower belt section 28 into which vertical section 26 feeds as shownin FIG. 2. Conveyer 27 may be an endless belt conveyer with its beltlying in he same plane and terminating at one end adjacent to section 28so as to discharge articles directly on section 28 to begin theirhelical conveyer ascent through outer path 12.

After the articles are conveyed to the top of the conveyer and thendownwardly through the inner helical path 14, they are unloaded fromlower belt section 20 by means of a second endless conveyer 29 similarto loading conveyer 27. Unloading conveyer 29 is positioned with itsinlet end adjacent the end of section 20 so that articles will bedischarged onto conveyer 29 as the belt moves downwardly from section 20into section 23.

Referring to FIG. 4, the conveyer belt is supported throughout itsmovement by means of a frame including inner and outer vertical supportmembers 30 and 32 which may be formed by the illustrated rectangularsteel tubing and which are anchored at the ground level indicated by 34.The vertical support members in each set are angularly spaced from eachother about the helical axes while being interconnected by chordalhorizontal support members 36 and 38 (see FIG. 3). In addition, thevertical support members in each set are interconnected by radialsupport members 40 which extend from a center post or column 44outwardly through chordal members 36 to chordal members 38. At thebottom of the conveyer, the outer and inner vertical support members areinterconnected by horizontal support members 46 while the inner verticalsupport members are connected by horizontal members 48 which radiatefrom center column 44.

The inner and outer helical paths of the belt are governed and supportedby horizontal support arms 50, 52 which project radially inwardly fromthe inner and outer vertical support members 30, 32 at helically spacedpositions about the center post 44 through which the common helical axisof both helical paths extends. Horizontal support arms 50, 52 aresecured at their outer ends to vertical support members 30, 32respectively with their inner ends being free such that horizontalsupport arms 50, 52 are cantilevered from the vertical support members.lnterconnecting successive horizontal support arms 50, 52 in each of thehelical paths are two pairs of runners 54 and 55 which extend helicallyabout the vertical helical axis. The runners in each pair 54, 55 areequally spaced from each other throughout their extent, and the conveyerbelt is adapted to horizontally rest on runners 54, 55 during itsmovement throughout the conveyer. If desired, a nylon or teflon liner orany other low friction surface (not shown) may be provided on the topsurfaces of runners 54, 55 to minimize sliding friction on the belt.

The conveyer belt is driven by engagement along its inner edge throughmeans of two concentric drive drums or cylinders generally designated 60and 62. Drum 60 is located inwardly of the inner helical path 14 whilethe other drum 62 is located outwardly of drum 60 between helical pathsl2 and 14 as indicated in FIGS. 3 and 4. Drums 60, 62 have a generallycylindrical frame comprised of plurality of vertically spaced concentriccircular frame portions 64 and 65; and elongated vertical angle members66 and 67 extending throughout the length of the drums while beingsecured to the circular frame portions 64, 65.

Drums 60 and 62 are mounted for rotation about the vertical helical axisby means of rollers 70, 72 suitably rotatably mounted through channels74, 75 to the bottom ends of the drums. Drum rollers 70, 72 are oncircular tracks 76, 77 formed by any suitable means. In the shownembodiment, the inner drum track 76 is supported on the radial supportmembers 48 while the outer drum track 77 is supported on horizontalsupport members 46 above the elevation of track 76. Any suitable trackarrangement may be provided in this regard. Moreover if desired, innerdrum 60 may be secured to a central rotatable drive post coinciding withthe axis of the helical path in which case rollers 70 would be omittedalong with the fixed central post support 44 for the frame.

As will be described subsequently in more detail, vertical angle members66, 67 are employed to drive the belt. For this reason, vertical anglemembers 66, 67 are secured in the drum frames with their corner edgesprojecting radially outwardly so as to be engageable in complimentaryrecesses formed in the inner edge of the belt as will be described.Sufficient angles are provided in each of the drums at appropriatecircumferential spacings depending on the size of the drums, the type ofbelt employed, etc. For example in one embodiment wherein the inner andouter drums are about 72 inches and 132 inches in diameter respectively,the angles may consist of one inch structural steel right angles withthe inner drum having approximately 90 angles equally spaced from eachother throughout the circumference, and the outer drum having I50 anglesequally spaced about the circumference thereof. Moreover the angles 66,67 are each positioned on the drum with their legs 66a, 66b, 67a, 67bextending at different angles to a line tangent to the drumcircumference and passing through the corners of the angles. Referringto FIGS. 5 and 7, it will be seen that leg 67a extends at an angle ofabout 5 (degrees) to a tangent line drawn through the corner of angle67. This positioning of the angles provides effective positiveengagement with the inner edge of the belt insuring that the belt willbe driven smoothly and without slippage.

In order to insure that tension is maintained on the belt when travelingthrough the upper transition section 16 between the inner and outerhelical paths, a plurality of drive angles 69 are secured to the uppersection of the inner drum 60 to project upwardly and outwardly at anincline as shown in FIG. 12. Drive angles 69 engage the inner edges ofthe belt as it moves through the transition section 16 to maintain asmuch drive continuity and support as possible on the belt. Drive angles69 may be secured in any suitable manner to angles 66 and/or circularframe member 64.

Referring now to FIG. 5, the drive drums 60 and 62 in the illustratedembodiment are rotated through means of sprocket chains 80 and 81respectively secured to the outer sides thereof to extend in ahorizontal plane throughout the circumference of the drums. Drive srockets 82 and 83 are suitably mounted for rotation about a fixedvertical axis and in mesh with sprocket chains 80 and 81 respectively todrive the drums upon rotation of the sprockets. Any suitable number ofidler sprockets 84 and 84a may also be provided in mesh with chains 80and 81 to insure that the drums are maintained in proper verticalalignment for rotation about the helical axis. A motor 86 operatingthrough a gear reducer 87 is employed to drive sprockets 82 and 83 atdifferent speeds through sprockets 88, 89 trained to sprockets 82, 83respectively. Sprockets 82 and 83 are of different sizes in order toproduce the required different speeds of rotation of drums 60, 62 sothat the speed of the outer edge of the belt on the small drum equalsthe speed of the outer edge of the belt on the large drum. By equatingthe ratio between the perimeters of the small and large drum to theratio between the sprocket diameters plus the width of the belt, thediameters of the sprockets 88, 89 can be calculated; it being understoodthat the drum perimeters and the width of the belt are known factors.Idler sprockets 84 and 84a are also trained to different size sprockets88, 89 which are of the same size as sprockets 88, 89 associated withdrive sprockets 82 and 83. Moreover sprockets 88, 89 are trained to aconveyer sprocket 90 which may be positively driven if desired.

Referring now to FIG. 7, the illustrated belt includes a plurality ofrods made from steel or any other suitable material extendingtransversely of the belt and being spaced from each other in thelongitudinal direction of the belt. Rods 100 are interconnected to eachother at their opposite ends by means of links 102 and 104 integrallyformed therewith. Links 104 at the outer edge of the belt are U-shapedor book shaped to receive the ends 101 of the adjacent rods in the biteor bend sections 105 thereof. It will be noted from FIG. 9 that smallspaces 106 exist between the extremities of the outer links 104 and theadjacent bite sections 105 of the next adjacent link. Consequently rods100 at their outer ends may undergo only a very limited amount ofcollapsing or extendible movement. In the position illustrated in FIGS.7 and 8, outer links 104 are in their fully extended ortensionedposition which they always occupy when the belt is in actual operationin the helical conveyer. Although not shown, outer links 104 may beconstructed so that they are not collapsible at all relative to eachother. This is because the outer links are always under tension when inactual use as will be explained below. In one specific embodiment of abelt wherein the width of the rods (belt width) is about 23 inches, thepitch of each outer link 104 is about 1 inch.

Links 102 which form the inner edge of the belt have a smallerlongitudinal dimension than outer links 104. Moreover inner links .102are made to be collapsible from an extended position shown in FIG. to aretracted or fully collapsed position shown in FIG. 1 1. In the specificbelt embodiment described above, inner links 102 have a pitch of aboutone-half inch when fully collapsed and a pitch of about threequarterswhen fully extended. The collapsibility of the inner links 102 enablesthe belt to adjust to the different diameters of drums 60 and 62. Whentraveling about the outer drum 62, the inner links 102 may assume anextended position which may be short of the fully extended positionshown in FIG. 7. Similarly, when traveling about the inner drum 62,innerlinks 102 may assume a collapsed position which may be short of thefully collapsed position.

in the specific type of belt disclosed, the collapsibility of the innerlinks 102 is achieved in manufacture by bending them laterally inwardlyof the belt or (towards the outer links) relative to belt rods 100 sothat adjacent links 102 may slide on and relative to each other withoutinterference between the link extremities 110 and the adjacent biteportions 1 12. This is illustrated in FIGS. 8 and 11 wherein inner links102 are in collapsed condition as opposed to their extended positionshownin FIG. 10.

In addition the inward bending of inner links 102 also provides aplurality of substantially right angled recesses 11 4 between successivelinks which are employed to receive drive angles 66 and 67 on the drumsfor moving the belt. It will be seen from FIGS. 7 and 8 that the cornersof drive angles 66, 67 engage positively within recesses 1 14 so thatupon rotation of the drums, the drive angles will push the inner edge ofthe belt forwardly without slippage.

In addition, the force imposed on the inner ends of rods 100 at recesses114 by angles 66 and 67 will cause the rods to pivot forwardly in thedirection of belt travel about their inner ends at bite section 116 thuscausing the outer ends of rods 100 to move forwardly. The result is thatthe outer edge of the belt will be under tension, that is with the outerlinks 104 fully extended throughout operation of the conveyer. This willserve to maintain the belt in the proper flat or horizontal positionwithout slack to facilitate effective drive of the belt.

Although one specific belt has been shown and described it should beunderstood that the invention encompasses use of any link or other beltwherein the outer edge of the belt has a greater radius of curvaturethan the inner edge of the belt and wherein the inner edge of the beltis collapsible and has a plurality of sharply defined recesses forreceiving driving members which not only are capable of moving the beltbut also in such a manner whereby the outer edge of the belt is alwaysunder tension.

Moreover although in the illustrated embodiment, the belt is drivenupwardly along the outer helical path and downwardly along the innerhelical path in the preferred embodiment this is reversed so that thebelt is-driven upwardly along the inner path and downwardly along theouter path. In this manner, only one third of the total belt weight ismoved upwardly inasmuch as the inner path obviously requires lessbelting than the outer path. Thus the preferred embodiment, does notrequire as much driving force for moving the belt, thereby enabling asmaller motor to be employed.

In addition, the preferred embodiment may employ annular sprocketsrather than the chains disclosed in the illustrated embodiment.

What is claimed is:

1. For use on a helical conveyer to be movable upwardly about a firsthelical path and then downwardly about a second direction of the belt,the belt having a longitudinally extending side edge to formthe inneredge of the belt when in use on the helical conveyer and a secondlongitudinallyextending side edge spaced transversely from said firstside edge by said cross members to form the outer edge of the belt whenin use on the helical conveyer, a first set of links interconnecting theends of the cross members at said first side edge and permitting theends of the cross members to movetowards and away from each othertopermit the belt to collapse or expand along said first side edge, asecond set of links interconnecting the ends of the belt at saidsecondside edge thereof, said first set of links each having alongitudinal dimension less than that of each of said second links, saidfirst set of links being dimensioned and shaped to permit adjacent linksto move towards and away from each other in the longitudinal directionof the belt a substantial distance relative to eachother to permit theinner edge of the belt to assume different curvatures during use on thehelical conveyer, and means defining a plurality of relatively sharpangled recesses adjacent each of the links in the first set forreceiving in positive engagement rotating angled drive members on thehelical conveyer whereby the belt may be positively driven by mechanicalpushing engagement along its inner edge.

2. The conveyer belt defined in claim 1 wherein said second set of linksare each formed such that they are essentially noncollapsible relativeto each other in the longitudinal direction of the belt.

3. An endless conveyer comprising in combination; support means definingconcentric helical paths including an inner path and an outer pathsurrounding the inner path, an endless belt.extending helically alongsaid paths and including transitional belt portions extending betweensaid inner and outer pathsat top and bottom end portions of theconveyer, and

means for driving said belt along said paths such that the belthelically ascends along one path and descends along the other,

and

wherein said paths have a common vertical axis, and

wherein said belt has inner and outer side edges made from links andwherein the links along the inner edges of the belt are collapsible toenable the inner edges of the belt to assume different curvatures whentraveling along said helical paths, and

wherein said belt has a plurality of means defining recesses extendingalong the inner side edge of the belt and wherein said drive meansincludes positive drive elements engaged in said recesses for pushingthe belt along said paths.

4. The conveyer defined in claim 3 wherein the links at said inner edgesof said belt are dimensioned less than the links at the outer side edgesof the belt.

5. The conveyer defined in claim 3 wherein said means for driving thebelt drives the belt helically upwardly along said inner path andhelically downwardly along said outer path.

6. The conveyer defined in claim '3 wherein said drive means furtherincludes a first generally cylindrical drive means mounted for rotationabout said axis inwardly of said innerhelical path, and a secondgenerally cylindrical drive means mounted for rotation between saidinner and outer helical paths, and wherein said positive drive elementsare fixed to said cylindrical drive means and extend verticallytherealong to be rotatable therewith while being in engagement with saidrecesses at the inner edge of said belt to drive the belt upon rotationof said cylindrical drive means.

7. The conveyer defined in claim 6 wherein said positive drive elementsare elongated angle members secured to said cylindrical drive means withtheir comers exposed to be received in the recesses of said belt.

8. The conveyer as defined in claim 7 wherein said angle members eachhave legs extending at different angles to a line tangent to theperiphery of the cylindrical drive means and passing through the cornerof the angle member.

9. The conveyer as defined in claim 7 wherein said angle members extendthroughout the length of said cylindrical drive means, and wherein thedrive angles in said first cylindrical drive means include top portionswhich extend outwardly and upwardly to engage the inner edge of thetransitional belt portion at the top of the conveyer.

10. The conveyer defined in claim 6 wherein said support means includesa first set of vertical stationary support members angularly spacedabout said vertical axis and being located between said inner and outerhelical paths, and a second set of vertical stationary support memberscircumferentially spaced about said vertical axis and positionedoutwardly of said outer helical path, and a plurality of support armssecured to said vertical support members in said first and second setand extending radially inwardly towards said vertical axis to definesaid inner and outer helical paths with the belt being engageablethereon.

11. The conveyer defined in claim 10 wherein said support means furtherincludes helical runners secured to said arms in said first and secondsets and extending helically throughout said inner and outer paths insupporting engagement under the belt.

12. The conveyer defined in claim 6 wherein said drive means furtherincludes first and second sprocket chains secured to said cylindricaldrive means respectively and extending circumferentially thereof, andfirst and second sprockets engaged in said chains respectively to drivesaid cylindrical drive means said first and second sprockets havingdifferent sizes to drive said first and second cylindrical drive meansat different speeds.

13. The conveyer defined in claim 6 further including inner and outerconcentric stationary circular tracks concentrically underlying saidfirst and second cylindrical drive means, and rollers mounted at thebottoms of said first and second cylindrical drive means and engaged onsaid tracks.

14. For use on a helical conveyer to be movable along a helical path, aconveyer belt comprising a plurality of elongated cross membersextending transversely of the belt and spaced in the longitudinaldirection of the belt, the belt having a longitudinally extending sideedge to form the inner edge of the belt when in use on the helicalconveyer and a second longitudinally extending side edge spacedtransversely from said first side edge by said cross members to form theouter edge of the belt when in use on the helical conveyer, a first setof links interconnecting the ends of the cross members at said firstside edge and permitting the ends of the cross members to move towardsand away from each other to permit the belt to collapse or expand alongsaid first side edge, a second set of links interconnecting the ends ofthe belt at said second side edge thereof, said first set of links beingdimensioned and shaped to permit adjacent links to move towards and awayfrom each other in the longitudinal direction of the belt a substantialdistance relative to each other to permit the inner edge of the belt toassume different curvatures during use on the helical conveyer, andmeans defining a plurality of relatively sharp angled recesses adjacenteach of the links in the first set for receiving in positive engagementrotating drive members on the helical conveyer whereby the belt may bepositively driven 'by mechanical pushing engagement along its inneredge, said port means defining a helical ath, an endless belt extend'nlgelically along said path, and rive means for driving said be t alongsaid path such that the belt helically moves along said path, and saidbelt comprising a plurality of elongated cross members extendingtransversely of the belt and spaced in the longitudinal direction of thebelt, the belt having a longitudinally extending side edge to form theinner edge of the belt when in use on the helical conveyer and a secondlongitudinally extending side edge spaced transversely from said firstside edge by said cross members to form the outer edge of the belt whenin use on the helical conveyer, a first set of links interconnecting theends of the cross members at said first side edge and permitting theends of the cross members to move towards and away from each other topermit the belt to collapse or expand along said first side edge, asecond set of links interconnecting the ends of the belt at said secondside edge thereof, said first set of links being dimensioned and shapedto permit adjacent links to move towards and away from each other in thelongitudinal direction of the belt a substantial distance relative toeach other to permit the inner edge of the belt to assume difierentcurvatures during use on the helical conveyer, and means defining aplurality of relatively sharp angled recesses adjacent each of the linksin the first set for receiving in positive engagement the rotating drivemeans on the helical conveyer whereby the belt may be positively drivenby mechanical pushing engagement along its inner edge, said first set oflinks each including a hooked shaped portion fixed to an associatedcross member and receiving a next adjacent cross member to interconnectsaid cross members, said hooked shaped portions extending inwardlytoward the center of the belt at an acute angle relative to theassociated cross member such that the adjacent hooked shaped portionsare slidable relative to and along each other into collapsed positions.

16. The conveyer defined in Claim 15 wherein each hooked shaped portionand its associated cross member define a recess.

17. The conveyer defined in claim 15 wherein said drive means includes agenerally cylindrical drive means rotatable about a vertical axis andsaid drive elements are angles fixed in angularly spaced relationshipabout the periphery of said cylindrical means.

18. The conveyer defined in claim 15 wherein said positive driveelements are elongated angle members secured to said cylindrical drivemeans with their corners exposed to be received in the recesses of saidbelt.

i l I

1. For use on a helical conveyer to be movable upwardly about a firsthelical path and then downwardly about a second helical path concentricto the first helical path, a conveyer belt comprising a plurality ofelongated cross members extending transversely of the belt and spaced inthe longitudinal direction of the belt, the belt having a longitudinallyextending side edge to form the inner edge of the belt when in use onthe helical conveyer and a second longitudinally extending side edgespaced transversely from said first side edge by said cross members toform the outer edge of the belt when in use on the helical conveyer, afirst set of links interconnecting the ends of the cross members at saidfirst side edge and permitting the ends of the cross members to movetowards and away from each other to permit the belt to collapse orexpand along said first side edge, a second set of links interconnectingthe ends of the belt at said second side edge thereof, said first set oflinks each having a longitudinal dimension less than that of each ofsaid second links, said first set of links being dimensioned and shapedto permit adjacent links to move towards and away from each other in thelongitudinal direction of the belt a substantial distance relative toeach other to permit the inner edge of the belt to assume differentcurvatures during use on the helical conveyer, and means defining aplurality of relatively sharp angled recesses adjacent each of the linksin the first set for receiving in positive engagement rotating angleddrive members on the helical conveyer whereby the belt may be positivelydriven by mechanical pushing engagement along its inner edge.
 2. Theconveyer belt defined in claim 1 wherein said second set of links areeach formed such thAt they are essentially non-collapsible relative toeach other in the longitudinal direction of the belt.
 3. An endlessconveyer comprising in combination; support means defining concentrichelical paths including an inner path and an outer path surrounding theinner path, an endless belt extending helically along said paths andincluding transitional belt portions extending between said inner andouter paths at top and bottom end portions of the conveyer, and meansfor driving said belt along said paths such that the belt helicallyascends along one path and descends along the other, and wherein saidpaths have a common vertical axis, and wherein said belt has inner andouter side edges made from links and wherein the links along the inneredges of the belt are collapsible to enable the inner edges of the beltto assume different curvatures when traveling along said helical paths,and wherein said belt has a plurality of means defining recessesextending along the inner side edge of the belt and wherein said drivemeans includes positive drive elements engaged in said recesses forpushing the belt along said paths.
 4. The conveyer defined in claim 3wherein the links at said inner edges of said belt are dimensioned lessthan the links at the outer side edges of the belt.
 5. The conveyerdefined in claim 3 wherein said means for driving the belt drives thebelt helically upwardly along said inner path and helically downwardlyalong said outer path.
 6. The conveyer defined in claim 3 wherein saiddrive means further includes a first generally cylindrical drive meansmounted for rotation about said axis inwardly of said inner helicalpath, and a second generally cylindrical drive means mounted forrotation between said inner and outer helical paths, and wherein saidpositive drive elements are fixed to said cylindrical drive means andextend vertically therealong to be rotatable therewith while being inengagement with said recesses at the inner edge of said belt to drivethe belt upon rotation of said cylindrical drive means.
 7. The conveyerdefined in claim 6 wherein said positive drive elements are elongatedangle members secured to said cylindrical drive means with their cornersexposed to be received in the recesses of said belt.
 8. The conveyer asdefined in claim 7 wherein said angle members each have legs extendingat different angles to a line tangent to the periphery of thecylindrical drive means and passing through the corner of the anglemember.
 9. The conveyer as defined in claim 7 wherein said angle membersextend throughout the length of said cylindrical drive means, andwherein the drive angles in said first cylindrical drive means includetop portions which extend outwardly and upwardly to engage the inneredge of the transitional belt portion at the top of the conveyer. 10.The conveyer defined in claim 6 wherein said support means includes afirst set of vertical stationary support members angularly spaced aboutsaid vertical axis and being located between said inner and outerhelical paths, and a second set of vertical stationary support memberscircumferentially spaced about said vertical axis and positionedoutwardly of said outer helical path, and a plurality of support armssecured to said vertical support members in said first and second setand extending radially inwardly towards said vertical axis to definesaid inner and outer helical paths with the belt being engageablethereon.
 11. The conveyer defined in claim 10 wherein said support meansfurther includes helical runners secured to said arms in said first andsecond sets and extending helically throughout said inner and outerpaths in supporting engagement under the belt.
 12. The conveyer definedin claim 6 wherein said drive means further includes first and secondsprocket chains secured to said cylindrical drive means respectively andextending circumferentially thereof, and first and second sprocketsengaged in said chaIns respectively to drive said cylindrical drivemeans said first and second sprockets having different sizes to drivesaid first and second cylindrical drive means at different speeds. 13.The conveyer defined in claim 6 further including inner and outerconcentric stationary circular tracks concentrically underlying saidfirst and second cylindrical drive means, and rollers mounted at thebottoms of said first and second cylindrical drive means and engaged onsaid tracks.
 14. For use on a helical conveyer to be movable along ahelical path, a conveyer belt comprising a plurality of elongated crossmembers extending transversely of the belt and spaced in thelongitudinal direction of the belt, the belt having a longitudinallyextending side edge to form the inner edge of the belt when in use onthe helical conveyer and a second longitudinally extending side edgespaced transversely from said first side edge by said cross members toform the outer edge of the belt when in use on the helical conveyer, afirst set of links interconnecting the ends of the cross members at saidfirst side edge and permitting the ends of the cross members to movetowards and away from each other to permit the belt to collapse orexpand along said first side edge, a second set of links interconnectingthe ends of the belt at said second side edge thereof, said first set oflinks being dimensioned and shaped to permit adjacent links to movetowards and away from each other in the longitudinal direction of thebelt a substantial distance relative to each other to permit the inneredge of the belt to assume different curvatures during use on thehelical conveyer, and means defining a plurality of relatively sharpangled recesses adjacent each of the links in the first set forreceiving in positive engagement rotating drive members on the helicalconveyer whereby the belt may be positively driven by mechanical pushingengagement along its inner edge, said first set of links each includinga hooked shaped portion fixed to an associated cross member andreceiving a next adjacent cross member to interconnect said crossmembers, said hooked shaped portions extending inwardly toward thecenter of the belt at an acute angle relative to the associated crossmember such that the adjacent hooked shaped portions are slidablerelative to and along each other into collapsed positions.
 15. Anendless conveyer comprising in combination; support means defining ahelical path, an endless belt extending helically along said path, anddrive means for driving said belt along said path such that the belthelically moves along said path, and said belt comprising a plurality ofelongated cross members extending transversely of the belt and spaced inthe longitudinal direction of the belt, the belt having a longitudinallyextending side edge to form the inner edge of the belt when in use onthe helical conveyer and a second longitudinally extending side edgespaced transversely from said first side edge by said cross members toform the outer edge of the belt when in use on the helical conveyer, afirst set of links interconnecting the ends of the cross members at saidfirst side edge and permitting the ends of the cross members to movetowards and away from each other to permit the belt to collapse orexpand along said first side edge, a second set of links interconnectingthe ends of the belt at said second side edge thereof, said first set oflinks being dimensioned and shaped to permit adjacent links to movetowards and away from each other in the longitudinal direction of thebelt a substantial distance relative to each other to permit the inneredge of the belt to assume different curvatures during use on thehelical conveyer, and means defining a plurality of relatively sharpangled recesses adjacent each of the links in the first set forreceiving in positive engagement the rotating drive means on the helicalconveyer whereby the belt may be positively driven by mechanical pushingengagement along its inner edge, said first set of links each includinga hooked shaped portion fixed to an associated cross member andreceiving a next adjacent cross member to interconnect said crossmembers, said hooked shaped portions extending inwardly toward thecenter of the belt at an acute angle relative to the associated crossmember such that the adjacent hooked shaped portions are slidablerelative to and along each other into collapsed positions.
 16. Theconveyer defined in Claim 15 wherein each hooked shaped portion and itsassociated cross member define a recess.
 17. The conveyer defined inclaim 15 wherein said drive means includes a generally cylindrical drivemeans rotatable about a vertical axis and said drive elements are anglesfixed in angularly spaced relationship about the periphery of saidcylindrical means.
 18. The conveyer defined in claim 15 wherein saidpositive drive elements are elongated angle members secured to saidcylindrical drive means with their corners exposed to be received in therecesses of said belt.